docs: def fill(h1: Histogram1D, ax: Axes, **kwargs):
      """Fill plot of 1D histogram."""
      show_stats = kwargs.pop("show_stats", False)
      # show_values = kwargs.pop("show_values", False)
      density = kwargs.pop("density", False)
      cumulative = kwargs.pop("cumulative", False)
      kwargs["label"] = kwargs.get("label", h1.name)
  
      data = get_data(h1, cumulative=cumulative, density=density)
      _apply_xy_lims(ax, h1, data, kwargs)
      _add_ticks(ax, h1, kwargs)
      _add_labels(ax, h1, kwargs)
  
      ax.fill_between(h1.bin_centers, 0, data, **kwargs)
  
      if show_stats:
          _add_stats_box(h1, ax, stats=show_stats)
      # if show_values:
      #     _add_values(ax, h1, data)
      return ax